Make sure clean <COMPONENT> cleans up obj dir

When user runs "./case.build --clean atm" some files
(Srcfiles, Depends etc) still remain in the atm build
directory.

This change was missed (changes in cesm Makefile was not ported to
the acme Makefile) in #1140

Fixes #1474
[BFB]

config/acme/machines/Makefile

@@ -836,38 +836,38 @@ $(COMPLIB): $(OBJS)
 
 cleanatm:
 	$(RM) -f $(LIBROOT)/libatm.a
-	cd $(EXEROOT)/atm/obj;  $(RM) -f *.o *.mod
+	$(RM) -fr $(EXEROOT)/atm/obj
 
 cleancpl:
-	cd $(EXEROOT)/cpl/obj;  $(RM) -f *.o *.mod
+	$(RM) -fr $(EXEROOT)/cpl/obj
 
 cleanocn:
 	$(RM) -f $(LIBROOT)/libocn.a
-	cd $(EXEROOT)/ocn/obj ; $(RM) -f *.o *.mod
+	$(RM) -fr $(EXEROOT)/ocn/obj
 
 cleanwav:
 	$(RM) -f $(LIBROOT)/libwav.a
-	cd $(EXEROOT)/wav/obj ; $(RM) -f *.o *.mod
+	$(RM) -fr $(EXEROOT)/wav/obj
 
 cleanesp:
 	$(RM) -f $(LIBROOT)/libesp.a
-	cd $(EXEROOT)/esp/obj ; $(RM) -f *.o *.mod
+	$(RM) -fr $(EXEROOT)/esp/obj
 
 cleanglc:
 	$(RM) -f $(LIBROOT)/libglc.a
 	$(RM) -fr $(EXEROOT)/glc
 
 cleanice:
 	$(RM) -f $(LIBROOT)/libice.a
-	cd $(EXEROOT)/ice/obj ; $(RM) -f *.o *.mod
+	$(RM) -fr $(EXEROOT)/ice/obj
 
 cleanrof:
 	$(RM) -f $(LIBROOT)/librof.a
-	cd $(EXEROOT)/rof/obj ; $(RM) -f *.o *.mod
+	$(RM) -fr $(EXEROOT)/rof/obj
 
 cleanlnd:
 	$(RM) -f $(LIBROOT)/liblnd.a
-	cd $(EXEROOT)/lnd/obj ; $(RM) -f *.o *.mod
+	$(RM) -fr $(LNDOBJDIR)
 
 cleancsmshare:
 	$(RM) -f $(CSMSHARELIB)